This multicenter, double-blind, randomized, controlled clinical trial has been designed to determine whether the addition of a multivitamin with high dose folic acid, pyridoxine (vitamin B6), and cyanocobalamin (vitamin B12) to best medical/surgical management and risk factor modification reduces recurrent cerebral infarction (primary end point) and myocardial infarction or fatal coronary heart disease (CHD, secondary endpoint) in patients with a nondisabling cerebral infarction (NDCI) who have basal homocyst(e)ine levels above 9.5 umol/L at screening. The fundamental eligibility criteria are the occurrence of a NDCI within 120 days prior to randomization and a qualifying homocyst(e)ine level. All patients will receive best management for risk factor reduction, which includes counseling and interventions for hypertension, high LDL (low-density lipoprotein), low HDL (high-density lipoprotein), tobacco use, diabetes and other recognized factors which add excess risk for cerebral and myocardial infarction. The study is designed to recruit 3600 patients (1800 in each of two groups) for 80% power for detection of a 30% treatment effect, allowing for 20% non-compliance in the high-dose treatment group.